Lazar mladen sereln



No. 6ll,288. Patented Sept. 27, I898 L. M. SERBAN.

THREE-SIDED OALK.

(Application filed Dec. '31, 1897.)

(lo Model.)

Q E &

UNITED STATES PATENT FErcE.

THREE-SIDED CALK.

SPECIFICATION forming part of Letters Patent No. 611,288, datedSeptember 27, 1898.

Application filed Decemb r 31; 1897. Serial No. 665,195. (No model.)Patented in Austria A gu t 22, 1896, No. 46/ 3,257,

- and in Hungary August 21, 1897,1Io. 9,397.

To a whom it may concern: I

' Be it known that I, LAZAR MLADEN SERBAN, a subject of the Emperor ofAustria-l-Iungary, residing in the city of Vienna, in the Province ofLower Austria, in the Empire of Austria- Hungary, have invented certainnew and useful Improvements in Three-Sided Oalks, (for which I haveobtained a patent in Austria,No. IS/3,257, dated August 22, 1896, and inHungary, No. 9,397, dated August 21, 1897,) of which the following is aspecification.

My invention relates to the production of three-sided calks possessingthe advantage of never becoming blunt,because there are no parallelplane surfaces on my improved calks and they remain sharp untilcompletely worn oif.

My improvements apply to blunt as well as to sharp calks. Further, theweight of my three-sided calks is less than that of other calksheretofore employed. N0 care need be taken when screwing them on,because they are effective in any position and do not slide on theground. The calks are easy to secure and to unscrew and enter or groundeasier than other calks.

My improved calks afford a sure protection until completely used up, asaccording to their special form no blunted edges or surfaces can occur.I

The invention is illustrated in the accompanying drawings, in which-'Figure 1 is an elevation of a pyramid-like three-sided horseshoe-call:with grooved or concaved surfaces. Fig. 2 is a bottom View of Fig. 4,and Fig. 3 is a perspective view of Fig. 4:. Fig. 4. is a cross-sectionof a calk of triangular sect-ion with equal shanks and plane surfaces.Fig. 5 is a section of a like calk with grooved or concaved surfaces,and Fig. 6 is a cross-section of a three-sided calk with inlaidindia-rubber.

penetrate the 7 As may be seen from the drawings, the calks consist of acalk-body proper, a, of triangular section, which has either three equalsides forming an equilateral triangle, Figs. 1 to 3, or two equal sidesforming an isosceles, Figs. 4 and 5, or unequal sides forming a scalene.To the calk body is connected the threaded calk-bolt Z) in any suitablemanner. The side surfaces may be plane, Fig. 4., or they may be plain orstraight, concaved or grooved, as shown in Figs. 1, 2, 3, and 5. Thecalkbody may be pyramid-like reduced with downward-converging sidesurfaces as sharp or pointed calks, as shown in Figs. 1, 2, and 3.

If desired, the calks maybe inlaid with india-rubber or the like, asshown in Fig. 0.

The calks are manufactured in any desired size and of any suitablematerialas, for instance, of cast or wrought iron, steel, or othermetals.

Having thus described my invention, what I claim therein as new, anddesire to secure by Letters Patent, is-- 1. An improved calk consistingof athreesided calk-body having pyramid-like converging side surfacesand forming at the lower end a second and short pyramid, and a threadedcalk-bolt, as specified.

2. An improved calk consisting of a threesided calk-body havingpyramid-like converging, grooved or concaved side surfaces and formingat the lower end a second and short pyaamid, and a threaded calk-bolt,as specifie In testimony whereof I have signed this specification inpresence of two subscribing witnesses.

LAZAR MLADEN SERBAN.

Witnesses:

HENRY G. CARPENTER, CHAs. E. CARPENTER.

